一共收集整理了图形20个，比较实用，同时也为了熟悉CSS的代码。整合了一下，有错误欢迎指出。

1.正方形



#square {

width: 100px;

height: 100px;

background: red;}


2.长方形

#rectangle {

width: 200px;

height: 100px;

background: red;}

3.左上三角

#triangle-topleft {

width: 0;

height: 0;

border-top: 100px solid red;

border-right: 100px solid transparent;

}


4.右上三角

#triangle-topright {

width: 0;

height: 0;

border-top: 100px solid red;

border-left: 100px solid transparent;}

5.左下三角

#triangle-bottomleft {

width: 0;

height: 0;

border-bottom: 100px solid red;

border-right: 100px solid transparent;

}

6.右下三角

#triangle-bottomright {

width: 0;

height: 0;

border-bottom: 100px solid red;

border-left: 100px solid transparent;

}

7.平行四边形

#parallelogram {

width: 150px;

height: 100px;

-webkit-transform: skew(20deg);

-moz-transform: skew(20deg);

-o-transform: skew(20deg);

background: red;

}

8.梯形

#trapezoid {

border-bottom: 100px solid red;

border-left: 50px solid transparent;

border-right: 50px solid transparent;

height: 0;

width: 100px;

}

9.六角星

#star-six {

width: 0;

height: 0;

border-left: 50px solid transparent;

border-right: 50px solid transparent;

border-bottom: 100px solid red;

position: relative;

}

#star-six:after {

width: 0;

height: 0;

border-left: 50px solid transparent;

border-right: 50px solid transparent;

border-top: 100px solid red;

position: absolute;

content: "";

top: 30px;

left: -50px;

}

10.五角星

#star-five {

margin: 50px 0;

position: relative;

display: block;

color: red;

width: 0px;

height: 0px;

border-right: 100px solid transparent;

border-bottom: 70px solid red;

border-left: 100px solid transparent;

-moz-transform: rotate(35deg);

-webkit-transform: rotate(35deg);

-ms-transform: rotate(35deg);

-o-transform: rotate(35deg);

}

#star-five:before {

border-bottom: 80px solid red;

border-left: 30px solid transparent;

border-right: 30px solid transparent;

position: absolute;

height: 0;

width: 0;

top: -45px;

left: -65px;

display: block;

content: '';

-webkit-transform: rotate(-35deg);

-moz-transform: rotate(-35deg);

-ms-transform: rotate(-35deg);

-o-transform: rotate(-35deg);

}

#star-five:after {

position: absolute;

display: block;

color: red;

top: 3px;

left: -105px;

width: 0px;

height: 0px;

border-right: 100px solid transparent;

border-bottom: 70px solid red;

border-left: 100px solid transparent;

-webkit-transform: rotate(-70deg);

-moz-transform: rotate(-70deg);

-ms-transform: rotate(-70deg);

-o-transform: rotate(-70deg);

content: '';

}

11.五边形

#pentagon {

position: relative;

width: 54px;

border-width: 50px 18px 0;

border-style: solid;

border-color: red transparent;

}

#pentagon:before {

content: "";

position: absolute;

height: 0;

width: 0;

top: -85px;

left: -18px;

border-width: 0 45px 35px;

border-style: solid;

border-color: transparent transparent red;

}

12.六边形

#hexagon {

width: 100px;

height: 55px;

background: red;

position: relative;

}

#hexagon:before {

content: "";

position: absolute;

top: -25px;

left: 0;

width: 0;

height: 0;

border-left: 50px solid transparent;

border-right: 50px solid transparent;

border-bottom: 25px solid red;

}

#hexagon:after {

content: "";

position: absolute;

bottom: -25px;

left: 0;

width: 0;

height: 0;

border-left: 50px solid transparent;

border-right: 50px solid transparent;

border-top: 25px solid red;

}

13.桃心

#heart {

position: relative;

width: 100px;

height: 90px;

}

#heart:before,

#heart:after {

position: absolute;

content: "";

left: 50px;

top: 0;

width: 50px;

height: 80px;

background: red;

-moz-border-radius: 50px 50px 0 0;

border-radius: 50px 50px 0 0;

-webkit-transform: rotate(-45deg);

-moz-transform: rotate(-45deg);

-ms-transform: rotate(-45deg);

-o-transform: rotate(-45deg);

transform: rotate(-45deg);

-webkit-transform-origin: 0 100%;

-moz-transform-origin: 0 100%;

-ms-transform-origin: 0 100%;

-o-transform-origin: 0 100%;

transform-origin: 0 100%;

}

#heart:after {

left: 0;

-webkit-transform: rotate(45deg);

-moz-transform: rotate(45deg);

-ms-transform: rotate(45deg);

-o-transform: rotate(45deg);

transform: rotate(45deg);

-webkit-transform-origin: 100% 100%;

-moz-transform-origin: 100% 100%;

-ms-transform-origin: 100% 100%;

-o-transform-origin: 100% 100%;

transform-origin :100% 100%;

}

14。无限大符号

#infinity {

position: relative;

width: 212px;

height: 100px;

}

#infinity:before,

#infinity:after {

content: "";

position: absolute;

top: 0;

left: 0;

width: 60px;

height: 60px;

border: 20px solid red;

-moz-border-radius: 50px 50px 0 50px;

border-radius: 50px 50px 0 50px;

-webkit-transform: rotate(-45deg);

-moz-transform: rotate(-45deg);

-ms-transform: rotate(-45deg);

-o-transform: rotate(-45deg);

transform: rotate(-45deg);

}

#infinity:after {

left: auto;

right: 0;

-moz-border-radius: 50px 50px 50px 0;

border-radius: 50px 50px 50px 0;

-webkit-transform: rotate(45deg);

-moz-transform: rotate(45deg);

-ms-transform: rotate(45deg);

-o-transform: rotate(45deg);

transform: rotate(45deg);

}

15.蛋

#egg {

display:block;

width: 126px;

height: 180px;

-webkit-border-radius: 63px 63px 63px 63px / 108px 108px 72px 72px;

border-radius: 50% 50% 50% 50% / 60% 60% 40% 40%;

}

16.提示对话框

#talkbubble {

width: 120px;

height: 80px;

background: red;

position: relative;

-moz-border-radius: 10px;

-webkit-border-radius: 10px;

border-radius: 10px;

}

#talkbubble:before {

content:"";

position: absolute;

right: 100%;

top: 26px;

width: 0;

height: 0;

border-top: 13px solid transparent;

border-right: 26px solid red;

border-bottom: 13px solid transparent;

}

17.十二角星

#burst-8 {

background: red;

width: 80px;

height: 80px;

position: relative;

text-align: center;

-webkit-transform: rotate(20deg);

-moz-transform: rotate(20deg);

-ms-transform: rotate(20deg);

-o-transform: rotate(20eg);

transform: rotate(20deg);

}

#burst-8:before {

content: "";

position: absolute;

top: 0;

left: 0;

height: 80px;

width: 80px;

background: red;

-webkit-transform: rotate(135deg);

-moz-transform: rotate(135deg);

-ms-transform: rotate(135deg);

-o-transform: rotate(135deg);

transform: rotate(135deg);

}

18.八角星

#burst-8 {

background: red;

width: 80px;

height: 80px;

position: relative;

text-align: center;

-webkit-transform: rotate(20deg);

-moz-transform: rotate(20deg);

-ms-transform: rotate(20deg);

-o-transform: rotate(20eg);

transform: rotate(20deg);

}

#burst-8:before {

content: "";

position: absolute;

top: 0;

left: 0;

height: 80px;

width: 80px;

background: red;

-webkit-transform: rotate(135deg);

-moz-transform: rotate(135deg);

-ms-transform: rotate(135deg);

-o-transform: rotate(135deg);

transform: rotate(135deg);

}

19.钻石

#cut-diamond {

border-style: solid;

border-color: transparent transparent red transparent;

border-width: 0 25px 25px 25px;

height: 0;

width: 50px;

position: relative;

margin: 20px 0 50px 0;

}

#cut-diamond:after {

content: "";

position: absolute;

top: 25px;

left: -25px;

width: 0;

height: 0;

border-style: solid;

border-color: red transparent transparent transparent;

border-width: 70px 50px 0 50px;

}

20.八卦

#yin-yang {

width: 96px;

height: 48px;

background: #eee;

border-color: red;

border-style: solid;

border-width: 2px 2px 50px 2px;

border-radius: 100%;

position: relative;

}

#yin-yang:before {

content: "";

position: absolute;

top: 50%;

left: 0;

background: #eee;

border: 18px solid red;

border-radius: 100%;

width: 12px;

height: 12px;

}

#yin-yang:after {

content: "";

position: absolute;

top: 50%;

left: 50%;

background: red;

border: 18px solid #eee;

border-radius:100%;

width: 12px;

height: 12px;

}